Variable-speed-transmission mechanism.



G. LEA.

VARIABLE SPEED TRANSMISSION MECHANISM.

APPLIGATION FILED 1111.22. 1912.

1 ,O90,401 Patented Mar. 17, 1914.

4 SHEETS-SHEET 1.

C. LEA.

VARIABLE SPEED TRANSMISSION MECHANISM.

APPLICATION FILED APR.22, 1912 1,090,401 Patented Mar. 17, 1914.

4 SHEETS-SHEET 2.

F I Q V) C. LEA.

VARIABLE SPEED TRANSMISSION MECHANISM.

APPLICATION FILED APR.22', 1912.

1,090,401. I Patented Mar. 17, 1914. I

4 SHEETS-SHEET 3.

7 55am 6?. W C/zarZea Lea.

a l I G LEA.

VARIABLE SPEED TRANSMISSION MECHANISM.

APPLICATION FILED APR.22, 1912.

1 ,090301 Patented Mar. 17, 1914.

4 SHEETS-SHEET 4.

mini) STATES PATEN l? onmcn.

CHARLES LEA, BOSTON, MASSACHUSETTS, ASSIGNOR TO AMERICAN WARP DRAW- ING MACHINE COIEPANY, A. CORPORATION OF MAINE.

VARIABLE-SPEED-TRANSMISSION MECHANISM.

oooaoi.

Specification of Letters Patent.

lr'atented Ma. l7, iota;

Application filed April 22, 1912. Serial No. 692,469.

I To all whom it may concern Be it knownthat 1, CHARLES Liana citizen of the United States and a resident of Boston, county of Sui'iolh', State of Massa-' chusetts, (whose post-office address is corner of Freeport, and Beach streets, Dorchester Massachusetts,)' have invented an Improve.

of, while its scope will he more particularly pointed out in the appended claims.

In the'drawings: Figure 1 is a plan view showing one form of the invention applied to the transmission of power from one shaft to a second parallel shaft. Fig. 2 is a side elevation on an enlarged scale showing the principal parts of the power transmitting mechanism of Fig. 1; Fig. 3 is a side elevation of the variable speed transmitting dc vice applied to a warp drawing-in mac ine; Fig. 4: is a lan view showing a modified form of dou le-acting transmission mechanism; Fig. 5 is'adetail thereof; Fig. 6 is a section on the line 6 6 in Fig. 4; Fig. 7 is a plan view showing a slightly modified form of double-acting speed transmitting device applied to a warp drawing machine; Fig. 8 is a side elevation of the transmitting mechanism shown in Fig. Z; 11d Fig. 9 is a detail in sectional elevation ta hen through one of the pawl supports.

Referring to the drawings and first to the illustrative embodiment of the invention which is shown in Figs. 1 and 2, I have there shown for purposes of illustration a driving shaft 1 from which it is required to transmit power at variable speeds to a parallel driving shaft 2. The specific application by which I have illustrated my invention here in disclosed is its application to a warp outside of the frame 6 drawing-in machine of the type shown in Patents Nos. 871,680 and 980,086, additional parts of which are illustrated in Figs. 3 and 7. The shaft 1 (see Figs. 3 and 7 constitutes the main driving shaft of the machine and serves to reci rocate the drawing-in needle 3 through t e sliding gear 4 (see Fig. 1) splmed on the shaft'l, the needle being mounted upon the traversing carrlage 5 adapted 'to slide along the machine frame 6. The driven shaft 2 constitutes a lead screw engaging the nut 7 attached to the carnage 5 and therefore serves to traverse the carriage. In practice it is required to vary the rate of the rectllinear traverse of the needle carriage 5 in relation to the number of needle picks per minute and therefore in relation to the speed of the main driving shaft 1 in order to adaptthe machine to warps containin a different number of threads per inch. or this purpose a positive speed change device is required, occupylng-but a small space and readily, but to secure the necessary accurately ad'ustable variation in t e traverse of the carriage.

It will be understoodthat while the hereinafter described form of s eed transmission device particularly a apted to meet the requirements for use in connection with a warp drawing-in machine, its application thereto is merely illustrative and the inventionin no way limited to that or any other particular use.

In the'form of the invention shown in Fig. 1, the lead screw shaft 2 is turned step by step by means of a ratchet wheel 8, the

latter connected to the end of the shaft 2 intervening clutch member 9 being provided, which, however, forms no essential part of the present invention. To engagathe ratchet teeth, there isprovided a pawl 10 pivoted upon the end of the swinging arm 11 and maintainedin engagement with the ratchet teeth by the spring 12. lhe arm 11 is carried by a sleeve journaled upon the, shaft 2 so as to be capable of oscillating about the same, the said sleeve also carrying the small spur gear 13, the teeth of which mesh with the'teeth of a rack 14, which latter is carried bythe reciprocatory arm 15. The op posite end of the arm is swiveled upon a stud 16 adjustably clamped to the face of the crank disk 1750 that by varying the ecof the machine, an-

ccntricity of the stud on the face of the disk the throw of the rack carryingmember can be varied.

Any suitable means for adjusting the. connecting arm may be employed, but as herein shown, the crank disk is provided with a T-slot 18 extending diametrically across the disk and adapted to receive the head of the stud 16 so that the latter may be clamped to the disk at any point along the slot.. Preferably, the stud is provided with an index finger 19 on one or both sides of the slit, which index finger. is adapted to register with graduations 20. These may be marked 7 according to any arbitrary scale either in terms denoting the number of needle picks per inch secured, or in any other terms desired. As the driving shaft 1 is turned at constant speed, the rack member is reciprocated, the teeth of the rack being held in engagement with the pinion by the upper. member of the connecting arm which slides along the top-of the pinion teeth. With each complete reciprocation of the rack, the awl arm executes one complete oscillation, t e extent of the oscillation and the number of teeth passed over, and consequently the angle to which the lead screw is turned, depending upon the distance the StHd'IG IS from the center of thecrank 17. By setting the stud.

near the outer end of the T-slot 1-8 the throw of the rack may be made great enough to oscillate the pawl arm through substantially 360 and turn'the lead screwthrough a complete revolution for-each revolution of the crank disk 17. On the other hand, the stud may be adjustably set in different positions toward the center of the disk to cut down the throw of the pawl arm and thereby reduce the rectilinear advance ofthe needle carriage by small gradations, the fineness of which depends merely upon thenumber and size of the teeth upon the ratchet 8.

The crank disk 17 may be driven from the main drivin shaft 1 by any suitable means, herein at re uced speed by means of the gear 21 attached to the crank disk and meshingwith the pinion 22 on the drive shaft 1.

In, the described form of transmitting device the movement of the driven member is intermittent, there being between each period of movement an equal period of dwell while the pawl is being moved back over the ratchet teeth. In Figs. 4 to 6, inclusive, there is illustrated a form of variable speed transmitting device similar in principle to that described, but wherein the driven member is moved both during the forward and backward movement of the connecting arm, the result being that the lead screw is given successive movements interrupted by an instant only of dwell occurring at the time the disk and its driving mechanism is similar to that shown in Figs. 1 and 2. The driven shaft 2 also has a similar ratchet-8 but the teeth thereof are'engplged by a pair of pawls 23 and 24, one wor 'ng on one side of the ratchet and the other on theoppositeside. The pawl 23 is pivoted on the arm 25 secured to the pinion 26 on one side of'the ratchet, while the awl 24: is pivoted on the arm 27 secured to tie pinion 28 on the other side of the ratchet. The pinion 28 meshes with the teeth 29 of the connecting member 30, the construction of the latter and its operation being similar to that of the connecting member 15 in the first form described. The pinion 26 meshes with the teeth 31 on a second connecting member-32, the construction whereof .is similar to that of the member 30 excepting that the teeth 31 mesh with the pinion 26 at a point diametrically opposite the oint of engagement of the pinion 28 and t of the two connecting members ,are ournaled upon a common crank pin 33, which latterinay be adjustable in the T-slot on the face of the crank disk so that the two connecting members are reciprocated in. unison. The result is that while one pawl arm is being moved to turn the ratchet, the remaining pawl arm is being moved in a reverse direction with its pawl slipping freely over the teeth. The moment the connecting member reverses its movement the awl on the ree rack 29. The opposite ends mainin arm grips the teet of theratchet and e ects a continuation of the rotary movement thereofin the same direction, while the first awl arm reverses and slips the larger wheel. The turning of the driven member therefore is effected alternately by the two pawls and their connecting members, the movement-producin engagement of one being immediately esta lished by the other on reversal of the connecting arms.

The ratchet 8 in this modification is made sufiiciently wide so that the awls can pass each other without inter erence, which would be necessitated when the strokes of the pawl arms is lengthened beyond 180.

In Figs. 7 to 9, inclusive, I have shown a variable speed transmission device similar in form to that last described, but of slightly difierent construction. In this. form upper and lower racks 34 and 35, respectively, are employed, but the same are united by end pieces 36 and 37 to form a single integral connecting member pivoted upon the crank pin 38. The upper rack member is staggered with relation to the lower rack member so that each member meshes with its re spective gear 39 and 40, the latter being mounted for free movement about the sleeve 41 keyed to the shaft 2. Between the gears and fixedly secured to the sleeve is the ratchet 43, the teeth of which are engaged back to get a. esh grip upon the teeth of p by pawls 44 and 45, respectively, carried by gear members 39 and 40. Each pawl (Fig. 9) is journaled upon a rock shaft 46 in a lug 47 projecting from the periphery of the gear, the sha t-46 having a flattened side engaged by the spring-pressed pin 48 by which it is held into engagement with the ratchet teeth under a yielding pressure.

The described form of variable speed transmitting device occu ies but a very small space at the end of tiie machine frame and is effective for obtaining a positive drive from the main drive shaft 1 to the parallel lead screw 2, whereby the rectilinear travel of the carriage 5 may be adjustedto any required rate 0 progression. When a plied to a warp drawing-in machine t e travel of the carriage may be set by means of the indicator and scale to provide for any desired number of picks per inch of car. riage travel.

While I have herein'shown and descrlbed for purposes of illustration one specific form of the invention, it is to be understood that the same is not limited to details of construction or relative form, or arrangement of parts or to the application herein made of the same, but that extensive deviations 'may be made therefrom without departing from the spirit thereof.

Claims- 1. In a variable speed transmission device, the combination with a driving member of a driven member, a ratchet connected to the driven member, a pawl and pawl carrying arm, the latter mounted to turn about the axis of the ratchet and im art to the latter a positive step by step ceding movement, a pinion connected to turn the pawl-carrying arm, a rack meshing with the inion, and an adjustable eccentric connection between the rack and the driving member thereby fixedly to adjust the strokeof the pawl by finely graduated steps 2. In a variable speed transmission. device, the combination with a driving member, a crank disk, a. driven member having connected thereto a ratchet wheel, a pawl and pawl-ca V ing arm, said pawl adapted to im art to t e ratchet a positive step by step ceding movement, a pinion connected toturn the pawl-carrying arm, a rack en- 'agmg the pinion, and means for adjustaly connecting the rack at difierent radial distan es from the center of the crank disk thertlaby adjustably to .fix the throw of the aw P 3. A variable speed transmission mechanism having a driving member and a driven member, a ratchet and pawl, a ratchet and pawl driving connection for the -driving member. including two reciprocatory driving ears, a rack connected to the driving mem r for reciprocating one of said gears, a rack member also connected to said driving member for simultaneously .but reversely reci rocating said second gear, a crank disk riven by said driving member, and an adjustable connection between the driving member and the driven member whereby the latter may be connected to the crank disk at different radial distances from the center of the latter.

4. In a variable s eed transmission mechanism, the combination with a rotary driving member, a pair of rack members eccentrically connected to the driving member, a driven member, a ratchet connected to said d iven member, a pair of pawls and pawl arms disposed in operative relation on op 0- site sides of said ratchet, a gear connect to each arm meshing each with one of the racks but in reverse relation, and means for adjusting the eccentricity of the rackmembers relative to the driving member whereby the awl-actuated movement of the ratchet may be adjusted by finely graduated steps.

7 In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses.

' CHARLES LEA.

Witnesses:

E. EDNA Srm, Tnomas B. Boo'rn. 

